Composite pressure sensitive adhesive sheet structure and process of making the same

ABSTRACT

A process in which a carrier strip has a release coated web marginally secured thereto, the latter releaseably adherently mounting a longitudinally extending tape having a pressure sensitive adhesive on its underside. The release coated strip is longitudinally severed with the line of severance being spanned by the adhesive coated tape. Subsequently, the combined span of the tape and a marginal portion of the release coated stock that is freely superposed on the carrier strip, are transversely slit defining a plurality of discrete pressure sensitive adhesive backed sections of tape, each provided with a corresponding tab by means of which each discrete section of tape can be peeled from the composite structure for application to another article. The process produces a roll of individually dispensible, pressure sensitive adhesive tape sections, each with its corresponding tab being so angularly related to the length of the composite structure as to facilitate winding up of the product, in the process of manufacture, to protectively enclose the tabs between successive coils of the carrier strip. Upon unwinding of the roll through a specially adapted guide means of a dispensing apparatus, each tab is individually projected out of the plane of the carrier strip to provide clearance for grasping a free end of the tab stripping the associated adhesive backed sheet article from the roll. The carrier strip and tape may have different characteristics of light reflectivity, controlling an automatic feed system for the dispensing apparatus, cooperatively associated with a photoelectric light cell or the like.

United States Patent 1 1 Buck I COMPOSITE PRESSURE SENSITIVE ADHESIVESHEET STRUCTURE AND PROCESS OF MAKING THE SAME Homer G. Buck, 803 S.Rimpau Ave., Los Angeles, Calif. 90005 Feb. 11, 1972 [76] Inventor:

[22] Filed:

' 21 Appl. No.1 225,668

Related U.S. Application Data [62] Division of Ser. No. 36,209, May 11,1970, Pat. No.

Primary Examiner-Douglas J. Drummon d Atl0rneyFulwider, Patton, Rieber,Lee & Utecht [57] ABSTRACT A process in which a carrier strip has arelease coated 1 Aug.7, 1973 web marginally secured thereto, the latterreleaseably adherently mounting a longitudinally extending tape having apressure sensitive adhesive on its underside. The release coated stripis longitudinally severed with the line of severance being spanned bythe adhesive coated tape. Subsequently, the combined span of the tapeand a marginal portion of the release coated stock that is freelysuperposed on the carrier strip, are transversely slit defining aplurality of discrete pressure sensitive adhesive backed sections oftape, each provided with a corresponding tab by means of which each discrete section of tape can be peeled from the composite structure forapplication to another article. The process produces a roll ofindividually dispen sible, pressure sensitive adhesive tape sections,each with its correspending tab being so angularly related to the lengthof the composite structure as to facilitate winding up of the product,in the process of manufacture, to protectively enclose the tabs betweensuccessive coils of the carrier strip. Upon unwinding of the rollthrough a specially adapted guide means of a dispensing apparatus, eachtab is individually projected out of the plane of the carrier strip toprovide clearance for grasping a free end of the tab stripping theassociated adhesive backed sheet article from the roll. The carrierstrip and tape may have different characteristics of light reflectivity,controllingan automatic feed system for the dispensing apparatus,cooperatively associated with a photoelectric light cell or the like.

5 Claims, 7 Drawing Figures COMPOSITE PRESSURE SENSITIVE ADHESIVE SHEETSTRUCTURE AND PROCESS OF MAKING THE SAME BACKGROUND OF THE INVENTION'ously manufacturing a roll of a composite strip structure providing aseries of individually dispensible pressure sensitive adhesive backedsheet articles, the resulting product, and improvements in apparatus fordispensing the same.

SUMMARY OF THE INVENTION The article of manufacture of this inventionincludes a base or carrier strip having a parallel strip or web mountedthereon in contacting superposition, the latter having a release coatedtop side on which a length of pressure sensitive adhesive backed sheetmaterial is releasably adherently mounted. One edge or marginal portionof the release coated stock is secured to the underlying correspondingmarginalportion of the base stock, the remaining width of the releasecoated stock remaining in freely contacting superposition on the basestock. The release coated stock is longitudinally severed but theseparate portions are held in contiguous abutment and against relativedisplacement by the pressure sensitive adhesive backed underside of atape. Discrete sections of the tape are formed by a transverse slittingoperating which simultaneously forms discrete areas of the free marginalportion of the release coated stock to provide tabs by means of whicheach separate label or the like can be peeled from the marginallysecured portion of the release coated stock. The area of mutual contactof each discrete section of tape with its corresponding tab is soadjusted, taking into consideration thenature of the release coating andthe tackiness of the pressure sensitive adhesive, that after the freedend of the tape section is placed in its finally intended position, thetab can be withdrawn from adherent contact with the underside of thearticle by laterally sliding the tab out of contact with the undersideof the tape article, afterwhich the then unadhered portion of thearticle can be pressed into adherent contact in its final position. I

The process of this invention lends itself to high speed production of alongitudinal series of butt cut, contiguous, pressure sensitive adhesivebacked sheet articles, each with its corresponding tab for removing eacharticle from the assembly forultimate application. The carrier or basestock, the release coated stock and an adhesive backed tape, are fed atthe same linear speed, continuously, to be sequentially brought intocontacting superposition. An adhesive is first applied to an edge of thecarrier strip after which the release coated stock is pressed thereonto,the two pieces of stock thereafter being adherently held against lateraldisplacement. Subsequently, the release coated stock is longitudinallysevered adjacent the area of marginally applied adhesive to define firstand second marginal portions of the release coated stock. The guiderolls and pressure rolls of the apparatus maintain the second marginalportion of the release coated stock in freely contacting superpositionon the carrier stock until the adhesive backed tape is linearly appliedacross the line of severance of the release coated stock, the twomarginal portions thereafter being tied against displacement by thetape. Subsequently, the second marginal portion of the release coatedstock and the tape are transversely severed into discrete portions atintervals spaced longitudinally of the composite structure.

The lines of severance of the tape and second marginal portion of therelease coated stock are preferably butt cuts and, preferably, disposedslant-wise, rather than along lines normal to a longitudinal edge of thecomposite structure. The lines of severance are so angularly related tothe normal that during winding up into a roll of the completed producteach discrete area of tape precedes its corresponding tab in entry intothe roll. As a consequence, each coil of individual tabs is fed into theroll without deformation and is protectively enclosed between successivecoils of the base stock or carrier strip.

The same preferred slant-wise severance of the tape and second marginalportion or tabs facilitates individual delivery of each section of tapeand its corresponding tab, either manually or in an automatic dispenser.In unwinding from a roll of the composite product, each tab precedes itsassociated section of tape whereby the free end of the tape or tab canbe grasped to peel the tape section from the first marginal portion of.the release coated stock. As thetabs formed out of the second marginalportion of the release coated stock are merelyin freely contactingsuperposition on the carrier strip, the latter may be deformed out ofthe plane of the tabs by an appropriate guide means, thus presentingeach individual tab projecting forwardly in a position for easy pickup,with clearance, out of the plane of the base or carrier stock. Bychoosing a reflectivity of the base stock which differs from thereflectiv' ity of the sheet article the composite strip assembly can beadvanced incrementally through an automatically controllable dispenserapparatus by properly optically orienting-a photoelectric cell system atthe dispensing station of the apparatus.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic perspective viewillustrative of the process of carrying out the invention;

FIG. 2 is a top plan view of a longitudinal segment ofthe completedcomposite product, portions of successive layers being broken away toillustrate distinct stages in the process of manufacture; I

FIG. 3 is a perspective view showing the means of application ofa'pressure sensitive adhesive backed sheet article made'in accordancewith the invention;

FIG. 4 is a view similar to FIG. 3 but showing the completedultimate-and use of the adhesive backed sheet article;

FIG. 5 is a somewhat schematic sectional view of an apparatus adaptedfor dispensing the individual pressure sensitive adhesive backedarticles;

FIG. 6 is a front view of the apparatus of FIG. 5; and

FIG. 7 is a transverse sectional view on the line 7-7 of FIG. 2, on anenlarged scale, showing the relationship of the several parts of asingle unit of the composite structure.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is usefulin the manufacture of a wide variety of pressure sensitive adhesivebacked flexible sheet articles, for example labels, markers,

tabs, bandages, film or tape splices, and other articles consisting ofan essentially flexible segment of sheet material bearing a pressuresensitive adhesive on the underside thereof. For purposes ofillustrating the process and resulting product of the invention, it willbe described in conjunction with the manufacture of a metallic facedsplicing tab of the type used in joining together adjacent ends of asound recording tape.

Referring to FIG. .1, there are shown portions of strips of a carrierpaper 10, a transfer adhesive tape 11, a release coated paper 12 and apressure sensitive adhesive backed tape 13. While not shown, it will beunderstood that each of these strips is fed from an appropriatelylocated supply roll thereof, all being mounted on an apparatus forsynchronously feeding the various strips through rolls and dies mountedon the apparatus at the same linear speed.

The carrier strip is preferably made from a hard, die-cutting,calendered stock and is fed from its supply roll over a guide roller 15whereon the transfer adhesive tape 11 comes into contactingsuperposition therewith, after having been trained over a guide roller16. The adhesive bearing tape 11 is one of a variety of commerciallyavailable products, typically a release coated paper bearing a stripablelayer of adhesive. It will be observed that the supply roll of thetransfer tape 11 is so aligned with the carrier strip 10 that theadhesive is laid along one margin or edge portion of the carrier strip,in a relatively narrow swath.

Thereafter, the layers 10 and 11 pass under a pressure roller 17,adapted to firmly press the adhesive of the tape 11 onto the carrierstrip 10, and around a series of guide rollers 18, 19 and 20. A roller21 takes the paper backing from the tape 11, leaving a swath of adhesive22 deposited on the upper surface of the carrier strip 10. The paperbacking of the tape 11 is spirally conducted away to be wound up on awaste roll 23.

The strip or web 12, on its upper side, is provided with a siliconerelease coating, which has relatively high release properties. As isshown in FIG. 1, the strip 12 is brought into parallel contactingsuperposition with the adhesive bearing carrier strip 10 between a pairof rollers 25 resulting in the two strips being secured together againstdisplacement, although the major portion of the width of the releasecoated strip 12 is merely in freely contacting superposition on thecarrier strip, rather than-being adhered thereto.

The marginally joined strips 10 and 12 are now passed over a roller 26,positioned in opposition to a rotary die 27 that is formed adjacent oneend with a circumferentially extending circular cutter 28. It will beobserved that the cutter 28 is offset from the adjacent edge of thecarrier strip 10 a distance slightly greater than the width of theadhesive strip 22, as best seen at the left hand end of FIG. 2. Thecutter 28 is adapted to slit only through the stock of the releasecoated strip 12, thus severing the strip 12 into a first marginalportion 12a and a wider, second marginal portion 12b, that remain incontiguous abutment along the line of severance 29 produced by therotary die 27. Thus, the first marginal portion 12a is essentiallypermanently adhered to the carrier strip 10 while the second marginalportion 12b remains in freely contacting superposition on the carrierstrip.

The roll of tape 13 employed in this example comprises a strip of thinmaterial coated with a pressure sensitive adhesive and covered withaluminum foil. The

tape may be a polyester film, such as Mylar, having the aluminum foillaminated to one surface thereof, the resulting laminated tape 13 thushaving a pressure sensitive adhesive coated underside. The tape 13 isrelatively narrow, as compared to the strips 10 and 12, and the supplyroll thereof is disposed in alignment with the line of severance 29.Accordingly, the tape 13 is fed onto the upper release coated side ofthe strip 12, beneath a roller 30, spanning the line of severance 29 totie the portions 12a and 12b in contiguous abutment.

The composite of the strips 10 and 12 and tape 13 is next passed over aroller 31 in opposition to a rotary die 32 that is formed with at leastone longitudinally extending cutting edge 33. For simplicity ofillustration, the rotary die 32 illustrated as being formed with but asingle cutting edge 33. It will however be appreciated that a pluralityof such cutting edges may be formed on the die and may take the form ofstraight rathern than helical cutting edges. In either event, thecutting edge 33 is adapted to slit the tape 13 and strip 12transversely, without penetrating the carrier 10, thus producing aplurality of butt cut slits 34 at intervals longitudinally of thecomposite strip. The slits 34 may, if desired, be along lines normal tothe longitudinal edges of the strips 10 and 12. However, it is preferredto form the rotary die 32 with helically extending cutting edges 33whereby to produce slant-wise slits 34 extending transversely of thetape 13 and strip 12, at angles other than normal to the longitudinaledges of the composite strip.

As a result of the slitting by the rotary die 32, the tape 13 is dividedinto a series of discrete sections 13a while the second marginal portion12b of the strip 12 is formed into discrete sections 12c providing apull tab for each section of the tape 13.

Finally, the composite product is wound into a roll 35. As the roll 35is turned in the take-up direction, the successive coils of the carrierstrip 10 receive the tabs 12c therebetween to protectively enclose them.In this connection, the slant-wise orientation of the slits 34 is suchthat each tape section 13a precedes its corresponding tab 12c in entryinto the roll 35. As a result, the otherwise free tabs 112a aresuccessively brought into the roll without deformation thereof and theroll 35 can be handled during transportation and in a dispenser withoutdanger of deforming the tabs.

It will be seen that the process just described provides a roll ofindividually dispensible pressure sensitive adhesive backed sheetarticles 130. Referring to the righthand end of FIG. 2, it can be seenthat each of the articles 13a may be individually removed from a lengthof the roll 35 merely by grasping the free end of a tab 12c to turn andpull it in a direction to peel the section 13a from the release coatedsurface of the marginal portion 120, the latter, of course, remainingglued to the carrier 10.

In this connection, attention is drawn to the different areas ofadhesive contact between the underside of the section 13a and themarginal portion 120, on the one hand, and the end of the correspondingtab 12c, on the other hand. Preferably, the greater area of contact iswith the first marginal portion 12a in order to insure peeling thesection 13a from the marginal portion 120, rather than accidentallyseparating the tab 12c from its associated section 13a. At the sametime, it is desirable to determine the optimum area of contact between atab 12c and the underside of a tape section 13a, taking intoconsideration the tackiness of the particular adhesive involved and thequalities of the release coating on the upper surface of the tab, suchthat the tab 12c may, in effect, be slid laterally from the section 13aupon final application of the tape section.

It will be observed that a section 130 of pressure sensitive backedadhesive sheet material is removed from the composite assembly merely bylifting and pulling on the tab 12c. The section 13c can thus be removedwithout involving any contact of the fingers with the adhesive on theunderside of the article 13a or even with the edges thereof. Referringto FIGS. 3 and 4, there are illustrated ends 45 and 46 of a recordingtape to be spliced together by application of one of the sections 13a.It will be seen that the section may be brought into parallel alignmentwith the ends 45 and 46, in position to span the abutting terminal endportions of the tapes and applied by manual pressure on top of thesection 13a. The tab 120 can thereafter be pulled laterally in thedirection of the arrow 47, in effect sliding the tab out of contact withthe underside of the section 13a. Thereafter, as is illustrated in FIG.4, finger pressure may be applied to deflect the previously unadheredportion of the section 13 a into contact with the tape end 46. Sincemanual contact with the adhesive on the underside of the tape section13a has been completely avoided, the integrity of the splice is greatlyenhanced. Referring to FIG. 2, note should also be taken of the oblongparallelogram configuration of the tape section 13a, achieved by-vir'tueof the slantwise slitting of the tape. In connection with the use ofsheet articles 13a intended for use in splicing sound recording tape andthe like this parallelogram configuration is of particular utility bothin attaining the proper alignment of the section 13a with the tape endsand, also, in connection with inhibiting mechanical displacement of thesection 13a from the splice once it has been finally applied.

In FIGS. 5 and 6 there is illustrated an apparatus adapted forautomatically dispensing the tape sections 13a from a roll 35. A housing50 incorporates a top wall 51 over which a weighted guide plate 52 issuperimposed. The top wall 51 and guide plate 52 thus desufficiently tobring the first tab 120 on the carrier strip 10 through the dispensingstation, with the corresponding tape section 13a at rest in a positionto intercept a ray 62 focused by means (not shown) onto the section 13a,to be reflected as a ray 63 directed into the photoelectric cell 60.

The photoelectric cell 60 comprises a portion of a circuit (not shown)including a relay and adapted to start and stop a motor orthe likedrivingly engaged to the wind-up drum 61. Thus, so long as a tapesection 13a is in position to reflect light from the source 59 onto thecell 60 the motor drive circuit remains open and the wind-up. drum 61 isdeactivated. However, upon the foremost and forwardly projecting tab 120being grasped and the corresponding tape section 13a being peeled fromthe first marginal portion 12a, the control circuit is closed, actuatingthe relay in order to turn the wind-up drum 61 through an arc sufficientto bring the next article 13a into the dispensing position. Thereupon,the light from the source 59 is again reflected from the upper surfaceof a section 13a into the photoelectric cell 60, deactivating thecontrol system. In this connection, while the control system justdescribed has been successfully employed with a metallic foil faced tapesection 13a, it will be appreciated that it may also be employed withsections 13a not incorporating any metallic face. All that is requiredis a differfine a channel therebetween through which the corn,-

posite is channelled towards a forward wall 53 of the housing. At itsrear end, the top plate 52 is formed with an upwardly and rearwardlyprojecting curved section 54 whereby individual tabs 12c will bedeflected downwardly onto the carrier strip '10, into contactingsuperposition thereon, as the roll 35 turns in the unwinding direction.

' The apparatus has a dispensing station at the junction of the forwardwall 53 and the top wall 51 of the housing. This dispensing stationincludes a roller 54 mounted for rotation on a horizontal axis and overwhich the carrier strip 10 is turned to be deflected downwardly forpassage through a clearance space provided between the front surface ofthe front wall 53 and a cover plate 55. Also mounted at the dispensingstation, on an appropriate bracket 57, is a housing 58 containing afocused light source 59 and photoelectric cell 60.

The roll 53 may be provided with a leader comprising a blank portion ofthe carrier strip 10 that is initially passed through the guide meansjust described to have 6 its end connected to a wind-up drum or spool61. A sufficient length of leader is provided whereby its end may be soconnected to the wind-up drum and advanced ence in reflectivity betweenthe upper surface of the particular tape section 13a under considerationand that portion of the underlying first marginal portion 12a normallycovered by the section 13a. For example, one of the surfaces maycomprise a specular reflector while the other surface may comprise orhave the characteristics of a diffuser, or both surfacesmmay be specularor diffuse, or may vary in color or hue, but appropriate filters may beinterposed in the line of the reflected ray 63 to discriminate betweenany differing characteristics of light reflected from two differentlyoptically reflecting surfaces.

Referring to FIG. 5, it will be seen that the guide means for thecomposite structure, at the dispensing station, is adapted to separatethe individual tabs from the normally underlying supporting strip 10.Thus, as the composite tape is fed outwardly of the housing50, since thefree end of each tab' precedes the tape section 13a to which it isjoined, a sufficient por tion of the length of the tab is supported inthe horizontal plane toproject forwardly from the front wall of thehousing while that portion of the carrier strip .10 originally disposedimmediately thereunder has been turned downwardly into thechannel-defined between the forward wall 53 and the cover plate 55. v

Although the invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred fonn has been made by way of example andthat numerous changes inthe details of construction and the combinationand arrangement of parts may be resorted to without departing from thespirit and the scope of the invention.

I claim:

I. A process of making aseries of individually dispensibleadhesive-backed flexible sheet articles comprising:

longitudinally aligning a carrier strip and a flexible web, leaving arelease coated side of said web exposed, in contacting superposition;

securing the strip and the web together longitudinally thereof, leavinga marginal portion of the web unsecured;

severing the unsecured portion of the web longitudinally thereof;

applying a strip of a pressure sensitive adhesivebacked tape materiallongitudinally of the web, onto the release coated side of the web andover the line of severance of the web, to secure the longitudinallysevered portions of the web together 10 while leaving a longitudinallyextending edge portion of the marginal portion of the web exposed;

and cutting the tape and web transversely at intervals spacedlongitudinally thereof for defining a series of individually dispensibleadhesive-backed sec tions of the tape adhesively joined to a series ofsevered sections of the marginal portion of the web providing tabs bymeans of which the corresponding sections of tape may be released fromadherence to that portion of the web secured to the carrier strip.

2. The process of claim 1 in which the cutting of the web and the tapeis along lines other than normal to the longitudinal edges of the web.

3. The process of claim 2 in which the carrier strip, release coated weband the tape are moved linearly in being assembled, said strip beingflexible,

and in which the lines along which the tape and web are out are slits atan angle such that each section of the tape linearly precedes thecorresponding tab portion of the web whereby to prevent lateraldisplacement of each tab as the assembled composite .of strip, web andtape is wound on a spool.

4. The process of claim 1 in which the area of mutual contact betweenthe underside of each section of tape and the release coated surface ofthe corresponding tab is less than the remaining area of the section oftape.

5. The process of claim 1 in which the carrier strip and the web areadhesively secured together by a strip of an adhesive that is laid ontothe carrier strip in advance of the strip and the web coming intocontacting superposition.

2. The process of claim 1 in which the cutting of the web and the tapeis along lines other than normal to the longitudinal edges of the web.3. The process of claim 2 in which the carrier strip, release coated weband the tape are moved linearly in being assembled, said strip beingflexible, and in which the lines along which the tape and web are cutare slits at an angle such that each section of the tape linearlyprecedes the corresponding tab portion of the web whereby to preventlateral displacement of each tab as the assembled composite of strip,web and tape is wound on a spool.
 4. The process of claim 1 in which thearea of mutual contact between the underside of each section of tape andthe release coated surface of the corresponding tab is less than theremaining area of the section of tape.
 5. The process of claim 1 inwhich the carrier strip and the web are adhesively secured together by astrip of an adhesive that is laid onto the carrier strip in advance ofthe strip and the web coming into contacting superposition.